Thermostatic control



---- July 22, 1947. L. M. BROWN 2 3 THERMOSTATIC CONTROL Filed Feb. 8, 1944 5; a: (Jaw r mum'- MMLJM v Lnms'MBnow/v.

i i BY", 1 Q 1 I control for controlling an electric control.

tion on line 4-4 of Fig. 3.

Patented July 22, 1947 2,424,433 THERMOSTATIC CONTROL Leslie M.

East Hartford, Conn., assignor toThe Silex Company, Hartford, Conn. Application February 8, 1944, Serial No. 521,508

This invention pertain to circuit controls and more particularly to a thermostatically operated device for controlling electric circuits in pressing irons such as disclosed in Patent No. 2,307,052, January 5, 1943, to Louis V. Lucia, for Circuit electric flat irons and connection therefor.

An object of the present invention is to provide a device of such character having means whereby' the same may be readily adjusted for circuit to accurately maintain a desired temperature.

A further object of the invention is to provide a thermostatically operated circuit control which is simple in construction, inexpensive to produce, and highly eilicient in its operation.

Other objects and advantages of this invention will be more clearly understood from the following description and from the accompanying drawings in which:

Fig. 1 is a side view in centrai vertical section showing my improved circuit control in elevation.

Fig. 2 is a plan view thereof ofv said circuit Fig. 3 is a rear view of the Fig. 4 is a side view in same in elevation. central vertical sec- Fig.- 5 is a plan view of the rocker arm carrying member.

Fig. 6 is an enlarged rear the eccentric member.

As shown in the drawings, the numeral I denotes an electric iron such as steam iron, having a sole plate 8 and an electrical resistance 1 view in elevation of 4 mounted thereon.

My improved circuit control includes a base member 3 which is preferably secured to the sole plate I by means of screws 9 and has vertical extensions l0ll from which project tabs ll which are adapted to prevent excessive displacement or said base by contacting an abutment, such as at ila, when subjected to undue pres. sure.

A plate I: i secured to said base member by means ofiasteners iS-lf and electrically insulated from said base member by a sheet II and washers ll of insulating material which are located between the said plate and the fasteners l3l3 and the base member I.

A separate plate I. is insulated from and mounted to the plate l2 by means of fasteners l'l-il. This plate It supports a cam-shaped contact member l8, such as shown and described in the above mentioned patent to Lucia, and is mounted within a U-shaped portion I I con- 7 Claims. (Cl. 200-138) taining the spring member 20 and the spacer 2|.

In addition thereto, a conductor strip 22 is provided between the spacer and the binder screw 23 for insuring proper electrical conduction between the contact member is and the said binder screw 23. v

The shaft 24, which carries the said contact member II, is provided with an extension v25 to suitably receive a handle 26 and a stop washer 21 is secured to said shaft and provided with stop portions 28 which engage a projection 29 on the U-shaped portion is to limit the rotational movement of said shaft and contact member l8. A rocker arm 30, carrying a movable contact Illa, is swivelly mounted on a shaft 3| which projects from an adjustable member 32 that is pivotally mounted to the plate II, by means of a pivot screw 33, and is provided with a fork-shaped portion having a notch 34.

An eccentric, preferably in the form of a disk 36 and having a bearing extension 36 and a nonaxial eccentric extension 31, is mounted between said member 32 and the plate II with the extension bearing within a recess 38 in the plate I! and the nonaxial extension 31 projecting through the notch 34. A washer 39 is placed around the pivot screw 33 between the member 32 and the plate l2 as a spacer to compensate for the disk portion 35.

80 A lock screw 40 is provided for securing the member 32 in adjusted position. This screw projects through an elongated opening 4| in the member 32 to permit movement thereof and is threaded to the plate 32.

The rocker arm 23 is provided with an extension 42 which engages an insulating abutment J3 carried by a bi-metallic thermostatically responsive bar 44 that is secured to the sole plate 6 and actuated by changes in temperatures therein to rock the rocker arm 29 and move the contact point" with relation to the cam-shaped contact member is.

The said rocker arm is connected, by a flexible conductor with an insulating covering 45, to the binder screw 48 to insure eiiicient electrical conduction from the contact through the said rocker arm and to the binding screw.

My improved circuit control may be provided with a binding post 41 which may extend from the base member 8 and is insulated therefrom by insulating washers II.

In the operation of the said circuit control, a conductor 49, from a source of energy indicated at '0, is connected by the binder screw 23. and another conductor II, from said source of energy, is connected to the binding post 41. One side of the heating element, indicated at I, is connected to the binding screw 41 by a conductor 52 and the other side of said heating element is connected by a conductor 53 to the binding screw 45.

The cam-shaped contact member is rotatable, by means of the handle 26, for operation of the circuit breaker to maintain the sole plate 6 at the desired temperatures The rocker arm 29 is actuated, by the bi-metallic member 44, to move the contact 30 into and out of contact with the member la in response to temperature changes in the said sole plate.

The said rocker arm is urged in the direction of the contact i8 and the extension 42 is retained into contact with the member 43, by means of a spring 54 which is anchored to the side of the rocker arm and to a notch 55 in an extension 56 which is provided on the plate 32.

When it is desired to adjust the position of the contact 30 with relation to the contact ll. for a desired change in the temperature maintained in the sole plate by the operation of said circuit control, such an adjustment may be made with the plate 32 by simply loosening the lock screw 40 and rotating the eccentric 35, by means of a screw driver or other suitable tool which may engage the slot 55 in the extension 31. Rotation of said member will rock the plate 32 on the pivot 33 and move the shaft 3! with the rocker arm 29 thereon. Contact between the point 43 and the extension 42 will cause the rocker arm to pivot on the said shaft 3| and thereby move the contact 30 nearer to or farther from the contact member 18. When the desired adjustment has been made, the plate 32 is locked in adjusted position by tightening the lock screw 40.

My improved circuit control therefore provides an efficient and easily operatable mechanism for positioning a movable contact with relation to a stationary contact thereon, such as the contact member l8, and further provides for adjustment of the circuit control to maintain desired temperatures within very close limits.

I claim:

1. A thermostatic circuit control of the character described comprising a frame, a stationary contact member, an adjustable member, a rocker arm pivotally mounted on said adjustable member, an electrical contact point on said rocker 'arm, thermally responsive means for operating said'rocker arm, and cam means for operating said adjustable member to move the pivotal point of said rocker arm and thereby adjust the position of said contact point relative to said stationary contact member.

2. A thermostatic circuit control of the character described comprising a frame, a stationary contact member, an adjustable member pivotally mounted on said frame, a rocker arm pivotally mounted on said adjustable member, an electrical contact point on said rocker arm, an eccentric rotatably mounted in said frame and adapted to operate said adjustable member for moving the same to adjust the position of said rocker arm relative to said stationary contact member, and means for locking said adjustable member in position on said frame.

3. A thermostatic circuit control of the character described having a stationary contact member mounted thereon, an adjustable member pivotally mounted on said frame, eccentric means for moving said adjustable member to change the position thereof, means for locking said adjustable member in position on said frame, a rocker arm carried on said adjustable member, an electrical contact point on said rocker arm movable relative to and engageable with said stationary contact member, and thermally responsive means for operating said rocker arm.

4. A thermostatic circuit control of the character described having a stationary contact member mounted thereon, an adjustable member pivotally mounted on said frame, eccentric means for moving said adjustable member to change the position thereof, means for locking said adjustable member in position on said frame, a rocker arm carried on said adjustable member, a, contact point on said rocker arm movable relative to said stationary contact member, and a bi-metallic member responsive to temperature changes for operating said rocker arm.

5. A thermostatic electric circuit control 01 the character described comprising a frame, a stationary contact member, a rocker arm having a contact point thereon for engaging said contact member, an adjustable member on said frame pivotally carrying said rocker arm, and adjustable means including an eccentric positioned between said adjustable member and frame, rotatable in said frame and adapted to move said adjustable member for changing the position thereof to vary the distance between said contact point and stationary contact member.

6. A thermostatic electric circuit control of the character described comprising a frame, a. stationary contact member, an adjustable member pivoted on said frame, a rocker arm pivoted on said adjustable member, a contact point on said arm adapted to engage said stationary contact member, and means for adjusting said adjustable member; said means comprising an actuating member having a disk portion positioned between said adjustable member and frame, an extension at one side of said disk portion rotatable'in said frame and a non-axial extension at the opposite side of said disk portion projecting through said adjustable member and adapted to move the same on its pivot upon rotation of said actuating member for varying the pivotal point of said rocker arm to adjust the position of the contact point relative to the stationary contact member.

'7. A thermostatic control for an electric circuit comprising a frame having a cam-shaped contact member rotatable therein, a member pivoted on said frame, a rocker arm pivotally carried on said member, a contact point On said rocker arm, thermally responsive means for operating said rocker arm to move said contact point relative to said cam-shaped contact member, and means for adiusting said member for varying the position of the rocker arm and second contact member thereon relative to said cam-shaped contact member.

LESLIE M. BROWN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

